The following relates generally to wireless communication, and more specifically to cooperative hidden node identification and management in a wireless communications system.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system). A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, each of which may be otherwise known as user equipment (UE).
Some modes of communication may enable communication between an access point (e.g., a base station) and a UE in a shared radio frequency spectrum band, or in different radio frequency spectrum bands (e.g., in a licensed radio frequency spectrum band and a shared or unlicensed radio frequency spectrum band) of a wireless network. A carrier in a shared radio frequency spectrum band may be available for use by devices intermittently due to contention for access to carriers of the shared radio frequency spectrum band between devices, such as between Wi-Fi devices operating according to Institute of Electrical and Electronics Engineers (IEEE) 802.11 protocols.
When contending for access to a wireless channel using shared radio frequency spectrum, a transmitter may perform a listen-before-talk (LBT) procedure to confirm that another transmitter is not using the wireless channel. The LBT procedure may include, for example, measuring energy received on the wireless channel and determining that the channel is currently in use by another transmitter when the energy level exceeds a threshold value. In some systems, devices may transmit preambles that provide information on the transmission, such as a duration of time of the transmission, that other devices may use to schedule subsequent LBT procedures. If two transmitters are sufficiently distant from one another the transmitters may concurrently transmit, as neither of the devices may receive sufficient energy from the other device to exceed the threshold energy level for identifying the other transmitter. However, if such a transmitting device is transmitting to a receiver that is located between the concurrently transmitting devices, the receiver may receive enough energy from the other device to interfere with the reception. The transmitter causing such interference may be referred to as a hidden node.